Some of these images were obtained from various sources. This site is not affiliated in any way with Apple Computer, Inc.
Maintained by John Calande.
This BLOG corrects much of the false early history of Apple Computer, Inc. I also show in detail, how to build an Apple 1 clone, and an BASIC expansion card.
I work as a Software Engineer. I am always looking for exciting, fun and challenging new projects. You can contact me at john.servodude at gmail.com

Saturday, March 28, 2009

Woz Monitor ASM

SOURCE: http://www.sbprojects.com/projects/apple1/wozmon.asm

;-------------------------------------------------------------------------;; The WOZ Monitor for the Apple 1; Written by Steve Wozniak 1976;;-------------------------------------------------------------------------

; KBD b7..b0 are inputs, b6..b0 is ASCII input, b7 is constant high; Programmed to respond to low to high KBD strobe; DSP b6..b0 are outputs, b7 is input; CB2 goes low when data is written, returns high when CB1 goes high; Interrupts are enabled, though not used. KBD can be jumpered to IRQ,; whereas DSP can be jumpered to NMI.

;-------------------------------------------------------------------------; Let's get started;; Remark the RESET routine is only to be entered by asserting the RESET; line of the system. This ensures that the data direction registers; are selected.;-------------------------------------------------------------------------

;-------------------------------------------------------------------------; Subroutine to print a byte in A in hex form (destructive);-------------------------------------------------------------------------